Sensitivity to Social Contingency and Positive Emotion in 2‐Month‐Olds

This study was aimed at sorting out conflicting results in the literature concerning 2‐month‐olds' sensitivity to interpersonal contingency, and investigated the potential role of infants' positive emotion in contingency detection. Infants were randomly assigned to an experimental group (EG) that was presented an uninterrupted live–replay–live sequence of three 30‐sec episodes of their mothers' communicative behavior using a double video TV paradigm, or to a control group (CG) that was presented an uninterrupted 90 sec of contingent maternal interactions. Infants of the EG grimaced more than infants of the CG only during the 2nd period of social exchange (replay vs. 2nd live period), but there was an increase of grimacing and a reduction in gazing during the 3rd period of televised interactions in infants of the CG. Each group was split into 2 subgroups a posteriori according to the presence or absence of smiling during the 1st contingent episode. Smiling infants of the EG reacted more negatively during the 2nd interaction period compared to other subgroups. These findings support the view that sensitivity, not fatigue or loss of interest to maternal stimulation, accounts for 2‐month‐olds' expressive changes during noncontingent maternal interactions; fatigue or loss of interest better explains the decline in attention and the increase of negative expressiveness during the last period of contingent interaction. The findings also suggest that the emotional climate of dyadic exchanges could be a contributing factor to infants' ability to detect the relations between their own actions and those of their social partners.     

When Infants Lose Exclusive Maternal Attention: Is It Jealousy?

To characterize infant reactions to jealousy evocation, 94 6‐month‐olds and their mothers were videotaped in an episode where the mothers directed positive attention toward a lifelike doll, and in 2 contrasting interactions: face‐to‐face play and a still‐face perturbation. Cross‐context comparisons of affects and behaviors revealed that jealousy evocation responses were distinguished by diminished joy and heightened anger and intensity of negative emotionality, comparable to levels displayed during the still‐face episode; heightened sadness, with durations exceeding those displayed during still‐face exposure; and an approach response consisting of interest, looks at mother, and diminished distancing, which was more pronounced than that demonstrated during play. Infants' heightened anger and sadness during jealousy evocation correlated with heightened maternal sensitivity and dyadic vocal turn‐taking, respectively, during play; and infants' diminished joy and interest during jealousy evocation were associated with heightened maternal withdrawal and intrusiveness, respectively, during play. Both fear and mother‐directed gaze were greater in girls. The discussion argues for interpreting the infant's mixed and agitated reaction to jealousy evocation as evidence of jealousy.     

Attention to Maternal Multimodal Naming by 6‐ to 8‐Month‐Old Infants and Learning of Word–Object Relations

We examined whether mothers' use of temporal synchrony between spoken words and moving objects, and infants' attention to object naming, predict infants' learning of word–object relations. Following 5 min of free play, 24 mothers taught their 6‐ to 8‐month‐olds the names of 2 toy objects, Gow and Chi, during a 3‐min play episode. Infants were then tested for their word mapping. The videotaped episodes were coded for mothers' object naming and infants' attention to different naming types. Results indicated that mothers' use of temporal synchrony and infants' attention during play covaried with infants' word‐mapping ability. Specifically, infants who switched eye gaze from mother to object most frequently during naming learned the word–object relations. The findings suggest that maternal naming and infants' word‐mapping abilities are bidirectionally related. Variability in infants' attention to maternal multimodal naming explains the variability in early lexical‐mapping development.     

Relation Between Maternal Contingent Responsiveness and Infant Social Expectations

This study investigated the relation between maternal contingent responsiveness and 4‐ and 5‐month‐old infants' (N = 64) social expectation behavior in a still‐face procedure. Mothers were asked to interact with their infants for 2 min (interactive phase), remain still‐faced for 1 min (still‐face phase), and resume interaction for 2 min. Mother and infant behavior was assessed for the frequency of infant and mother smiles, mother smiles that were contingent to infant smiles and infant smiles were contingent to mother smiles during the interactive phase, and infant social bids to mother during the still‐face phase. Hierarchical regression showed that mother contingent smiles during the interactive phase accounted for unique variance in infant social bids during the still‐face phase beyond that accounted for by the frequency of mother and infant smiles during the interactive phase. These results support the view that young infants' social expectations and sense of self‐efficacy are formed within their interactions with their caregivers.     

Sensitivity to Social Contingency From Mothers and Strangers in 2‐, 4‐, and 6‐Month‐Old Infants

Infants' sensitivity to changes in social contingency was investigated by presenting 2‐, 4‐, and 6‐month‐old infants with 3 episodes of social interaction from mothers and strangers: 2 contingent interactions and 1 noncontingent replay. Three orders were presented: (a) contingent, noncontingent, contingent; (b) contingent, contingent, noncontingent; and (c) noncontingent, contingent, contingent. Contingency and carryover effects were shown to both mothers and strangers in the different orders of presentation. Infants were more visually attentive to contingent interactions than to the noncontingent replay when contingent interactions occurred prior to the replay, and the infants' level of attention to the noncontingent replay carried over to subsequent contingent interactions. The 4‐ and 6‐month‐old infants showed contingency and carryover effects by their visual attention and smiling. Examination of effect sizes for attention suggests 2‐month‐old infants may be beginning to show the effects. Reasons for age changes in sensitivity to social contingency are discussed.     

Infants' Response to Maternal Mirroring in the Still Face and Replay Tasks

Infants' response to maternal mirroring was investigated in 4‐month‐old infants. Mother–infant dyads participated in the still face and replay tasks. Infants were grouped by those whose mothers did and did not mirror their behavior in the interactive phases of the tasks. In the still face task, infants with maternal mirroring showed more attention, smiling, and positive vocalizations across the phases, although both groups of infants demonstrated the still‐face effect with attention and smiling. Infants' social bidding to the mother during the still‐face phase correlated with mothers' mirroring behavior. In the replay task, infants with maternal mirroring demonstrated carryover effects with smiling; infants without maternal mirroring showed no awareness of change in their mothers' behavior. In both the still face and replay tasks, infants with maternal mirroring were more engaged with their mothers. Results suggest that maternal mirroring of infants' behavior affects infants' detection of, and response to, reciprocal interaction.     

Effects of Maternal Responsiveness on Infant Responsiveness and Behavior in the Still‐Face Task

The effects of maternal responsiveness on infant responsiveness and behavior in the Still‐Face Task were longitudinally examined through infants' first 3 months. Maternal vocal responsiveness and infant vocal and smiling responsiveness significantly increased when infants were 2 months of age. Mothers showed continuity of individual differences in vocal responsiveness from the infants' newborn period. Maternal responsiveness predicted infant responsiveness within and across sessions. Compared with infants with low‐responsive mothers, infants with high‐responsive mothers were more attentive and affectively engaged during the Still‐Face Task from 1 month of age. Infants with high‐responsive mothers discriminated between the task phases with their smiling at 1 month, a month before infants with low‐responsive mothers did so. Infants in both groups discriminated between the phases with their attention and nondistress vocalizations throughout their first 3 months. Results suggest that maternal responsiveness influences infant responsiveness and facilitates infants' engagement and expectations for social interaction.     

Parental Speech at 6 Months Predicts Joint Attention at 12 Months

In a prospective longitudinal study of a representative community sample (N = 264), mothers' references to infants' mental states were coded during a topic‐sharing task in the home at 6 months. Joint attention behaviour was assessed in the laboratory at 12 months. Individual joint attention skills (gaze following, gaze alternating, and declarative pointing) were significantly inter‐correlated, with a single factor accounting for 68% of the variance. Mothers' references to infants' mental states at 6 months predicted infants' joint attention at 12 months. The association was not explained by sociodemographic characteristics of the family, the mother's mental state, or by the quantity or acoustic properties of her speech. However, variability in pitch of maternal speech was an independent predictor of the infants' later joint attention skills. Taken together, these findings suggest that mothers' infant‐directed speech fosters infants' attentive participation in topic‐sharing interactions, which in turn provide an important arena in which joint attention skills develop over the first year of life.     

Infants' Transitions out of a Fussing/Crying State Are Modifiable and Are Related to Weight Status

Currently, about 10% of infants have a weight for length greater than the 95th percentile for their age and sex, which puts them at risk for obesity as they grow. In a pilot obesity prevention study, primiparous mothers and their newborn infants were randomly assigned to a control group or a Soothe/Sleep intervention. Previously, it has been demonstrated that this intervention contributed to lower weight‐for‐length percentiles at 1 year; the aim of the present study was to examine infant behavior diary data collected during the intervention. Markov modeling was used to characterize infants' patterns of behavioral transitions at ages 3 and 16 weeks. Results showed that heavier mothers were more likely to follow their infants' fussing/crying episodes with a feeding. The intervention increased infants' likelihood of transitioning from a fussing/crying state to an awake/calm state. A shorter latency to feed in response to fussing/crying was associated with a higher subsequent weight status. This study provides preliminary evidence that infants' transitions out of fussing/crying are characterized by inter‐individual differences, are modifiable, and are linked to weight outcomes, suggesting that they may be promising targets for early behavioral obesity interventions, and highlighting the methodology used in this study as an appropriate and innovative tool to assess the impact of such interventions.     

The Effect of Social Responsiveness on Infants' Object‐Directed Imitation

Previous research has demonstrated that social interactions underlie the development of object‐directed imitation. For example, infants differentially learn object action sequences from a live social partner compared to a social partner over a video monitor; however, what is not well understood is what aspects of social interactions influence social learning. Previous studies have found variable influences of different types of caregiver responsiveness on attention, language, and cognitive development. Therefore, the purpose of this study was to examine how the responsive style of a social partner influenced the learning of object‐directed action sequences. Infants interacted with either a sensitive or redirective experimenter before the learning trial. Results revealed infants changed their patterns of engagement; infants interacting with a sensitive experimenter had longer periods of attentional engagement than infants interacting with a redirective experimenter. Furthermore, during the learning trial, the amount of sensitivity during interaction with the social partner predicted learning scores. These findings suggest that infants' attention is influenced by social partners' interactive style during ongoing interaction, which subsequently affects how infants learn from these social partners.     

Do Infants Recognize Engagement in Social Interactions? The Case of Face‐to‐Face Conversation

This study explores 12‐month‐olds' understanding of face‐to‐face conversation, a key contextual structure associated with engagement in a social interaction. Using a violation‐of‐expectations paradigm, we habituated infants to a “face‐to‐face” conversation, and in a test phase compared their looking times between “back‐to‐back” (conceptually novel) and “face‐to‐face” (conceptually familiar) conversations, while simultaneously manipulating perceptual familiarity in a 2 × 2 factorial design. We also analyzed dynamic changes in pupil dilation, which are considered a reliable measure of cognitive load that may index processing of social interactions. Infants looked relatively longer at perceptual changes (new speaker positions) but not at conceptual change (back‐to‐back conversation), suggesting that face‐to‐face conversation may not elicit particular expectations, and so may not carry any particular conceptual significance. Moreover, on the first test trial, larger pupil dilation was observed for familiar conditions, suggesting that familiarity with perceptual features could enhance processing of conversations. Thus, this study undermines assertions regarding infants' conceptual understanding of the social signals underlying engagement. Infants may rather recognize such signals through their perceptual familiarity and associated positive feelings. This may then increase their engagement when observing and participating in others' collaborative activities, in turn allowing for the development of knowledge regarding others' intentions.     

Infant Brain Responses to Object Weight: Exploring Goal‐Directed Actions and Self‐Experience

Recent work has suggested the value of electroencephalographic (EEG) measures in the study of infants' processing of human action. Studies in this area have investigated desynchronization of the sensorimotor mu rhythm during action execution and action observation in infancy. Untested but critical to theory is whether the mu rhythm shows a differential response to actions which share similar goals but have different motor requirements or sensory outcomes. By varying the invisible property of object weight, we controlled for the abstract goal (reach, grasp, and lift the object), while allowing other aspects of the action to vary. The mu response during 14‐month‐old infants' own executed actions showed a differential hemispheric response between acting on heavier and lighter objects. EEG responses also showed sensitivity to “expected object weight” when infants simply observed an experimenter reach for objects that the infants' prior experience indicated were heavier vs. lighter. Crucially, this neural reactivity was predictive—during the observation of the other reaching toward the object, before lifting occurred. This suggests that infants' own self‐experience with a particular object's weight influences their processing of others' actions on the object, with implications for developmental social‐cognitive neuroscience.     

Infants' Ability to Distinguish Between Intentional and Accidental Actions and Its Relation to Internal State Language

The experiment reported here investigated infants' concept of intention, as well as the relation among intention understanding, general productive vocabulary, and internal state language production during the 2nd year. Results from an imitation task indicated that 18‐month‐olds are better able to differentiate between intentional and accidental actions than 14‐month‐olds. Although there was no relation between infants' performance on the intention task and their general productive vocabulary, internal state language production at 30 months was predicted by infants' ability to differentiate between intentional and accidental actions about a year earlier. These findings shed light on the developmental progression of infants' concept of intention, as well as on the continuity between infants' understanding of intentional action and their ability to use internal state words.     

The Cat is out of the Bag: The Joint Influence of Previous Experience and Looking Behavior on Infant Categorization

We examined the effect of 4‐month‐old infants' previous experience with dogs, cats, or both and their online looking behavior on their learning of the adult‐defined category of cat in a visual familiarization task. Four‐month‐old infants' (N = 123) learning in the laboratory was jointly determined by whether or not they had experience with pets at home and how much they shifted their gaze back and forth between the stimuli during familiarization. Specifically, only infants with pets at home who also exhibited high levels of switching during familiarization remembered the individual cat exemplars or formed a summary representation of those cats. These results are consistent with recent theorizing about the processes of how infants' categorical representations are formed, and provide new understanding into how infants' categorization unfolds over time.     

Temperamental Susceptibility to Parenting among Preterm and Full‐Term Infants in Early Cognitive Development

The current study examined the interaction between premature birth, temperamental reactivity, and parenting in early cognitive development. Participants were 142 infants (80 preterm; 62 full term) and their parents. Parent–child interactions (maternal, paternal, and co‐parental) were observed at age 6 months to assess parental structuring behaviors. Additionally, both parents reported on infants' temperamental reactivity. At 12 months of age, infants' cognitive abilities were assessed. Consistent with the diathesis–stress model, preterm infants had lower cognitive outcomes than full‐term infants when exposed to low levels of co‐parental structuring, but functioned similarly when exposed to high levels of co‐parental structuring. However, temperamental reactivity moderated this effect: Infants who carried one susceptibility factor (i.e., premature birth or reactive temperament) were similarly affected by co‐parental structuring, whereas infants who carried two or no susceptibility factors were not. Furthermore, consistent with the differential susceptibility hypothesis, infants with highly reactive temperaments had lower cognitive functioning when exposed to low maternal structuring, but higher cognitive functioning when exposed to high maternal structuring compared to infants with lower reactivity. Results from this study highlight the importance of considering both temperamental reactivity and quality of parenting in understanding preterm infants' early cognitive vulnerability.     

Depressed and Well Mothers' Emotion Interpretation Accuracy and the Quality of Mother—Infant Interaction

The inadequate parenting associated with mothers' depression may be related to mothers' problems in interpreting infants' emotional expressions. The relations between depressed and well mothers' accuracy at interpreting babies' facial expressions and the quality of the mothers' interactions with their infants were examined. In partial support of our hypotheses, depressed mothers' level of depressive symptoms was associated with less accuracy, especially regarding positive emotions. Contrary to expectations, depressed mothers did not differ from well mothers in terms of their emotion accuracy. Furthermore, depressed mothers' accuracy at interpreting infants' emotions was not significantly related to the quality of their interaction with their infants; in contrast, well mothers' accuracy for infants' negative emotions was associated with better interaction quality. These findings provide new information about depressed mothers' emotional interpretations and their parenting. The different pattern of findings for depressed and well mothers suggests that other mediating factors are important, which are discussed.     

The Value of Vocalizing: 10‐Month‐Olds' Vocal Usage Relates to Language Outcomes at 15 Months

The interaction between infant's communicative competence and responsiveness of caregivers facilitates the transition from prelinguistic to linguistic communication. It is thus important to know how infants' communicative behavior changes in relation to different caregiver responses; furthermore, how infants' modification of communicative behavior relates to language outcomes. We investigated 39 10‐month‐old infants' communication as a function of mothers' attention and responses and the relationship to language outcomes at 15 months. We elicited infants' communicative behavior in three conditions: (1) joint attention: Mothers were visually attending and responding to infants' attention and interest; (2) available: Mothers were visually attending to infants, but not responding contingently to infants' attention and interest; (3) unavailable: Mothers were not attending to infants nor responding to them. Infants vocalized more when mothers attended and responded to them (conditions 1 and 2) than when mothers did not (condition 3), but infants' gesture and gesture‐vocal production did not differ across conditions. Furthermore, infants' production of a higher proportion of vocalizations in the unavailable condition relative to the joint attention condition correlated with, and predicted, infants' language scores at 15 months. Thus, infants who appear to be aware of the social effects of vocalizations may learn words better.     

Maternal Depressive Symptoms and 6‐Month‐Old Infants' Sensitivity to Facial Expressions

We examined 6‐month‐old infants' abilities to discriminate smiling and frowning from neutral stimuli. In addition, we assessed the relationship between infants' preferences for varying intensities of smiling and frowning facial expressions and their mothers' history of depressive symptoms. Forty‐six infants were presented pairs of facial expressions, and their preferential looking time was recorded. They also participated in a 3‐min interaction with their mothers for which duration of both mother and infant gazing and smiling were coded. Analyses revealed that the infants reliably discriminated between varying intensities of smiling and frowning facial expressions and a paired neutral expression. In addition, infants' preferences for smiling and frowning expressions were related to self‐reports of maternal depressive symptoms experienced since the birth of the infant. Potential implications for social cognitive development are discussed.     

Infant Looking Behavior in Ambiguous Situations: Social Referencing or Attachment Behavior?

Is infant looking behavior in ambiguous situations best described in terms of information seeking (social referencing) or as attachment behavior? Twelve‐month‐old infants were assigned to 1 of 2 conditions (Study 1); each infant's mother provided positive information about an ambiguous toy and an experimenter provided positive information. In Study 2, 12‐month‐old infants were assigned to 1 of 3 conditions: mother provided positive information about the toy, mother was inattentive, or mother provided negative information; the experimenter was inattentive. The infants preferred to look at the experimenter in almost all conditions and they regulated their behavior in accordance with information obtained from the experimenter. None of the studies lends support for an explanation in terms of behaviors deriving from the attachment system, and they raise questions concerning social referencing interpretations of infants' looking behavior. Other alternatives for explaining infant looking behavior in social referencing situations (e.g., associative learning) are discussed.